Liquid-level indicator



P. J. SEFERLIS LIQUID LEVEL INDICATOR April 21, 1931.

Filed!e Aug. 14, 1926 all K NVENTOR.

M41 l I Y l f f RNEYS.

Patented Apr. 21., 1931 PETER J'. SFFERLS, OF CORTLAND, NEVJ YORK LIQUID-LEVEL INDICATOR Application filed August 14,1926. Serial No. 129,286.

This invention relates to Aa liquid'deptlfi or level gage of the class set forth in my Patentsv No. 1,560,350, November 3, 1925, and' No. 1,575,284, March 2, 1926, in that it is adapted Vto vbe mounted upon the instrument board or other suitable partV of a motor vehicle where it is readily visible by the operator for determining the amount of liquid such as gasoline, or other liquid fuel, although it is equally applicable for other uses in which it Ais desired to ascertain the amount of liquid in a reservoir. l

In the devices set forth in the patents refvferred to the gage is provided with a suitable stand pipe or tubular column for receiving one end of a pipe having its olhciond connected to the reservoir containing the liquid, the depth or level of which is to be measured or ascertained through the medium of ,the gage, said stand pipe or tubular` column having its lower end connected `to a supplemental reservoir which in turn is connected to a suitable depth vorlevel indicatingvdevi'ce 4of the fioat and dial type as shownV in the earlier patentor of the tubular gage type shown in the later patent.

These gagesralso include means whereby air mayl be forced through the indicating device and its connections with the main reservoir to overcome any inaccuracies `of the reading of the'gage due to the effect Vof varying temperatures ofV any of the connections between the main supply tank and gage and while all of these adjuncts are found to be highly eflicient l 'have found that the efiiciency of such apparatus may begreatly increased by certain improvements forming the Subj ect matter ofthe present invention.

For example, one "of the objectsis to con- ,nectthe supplemental'reservoir with the tubular sight gage by means of a straight restricted tube having one end disposed in the supplementaly reservoir near 4the bottomV thereof and itsother end extending into the 'i sight tube or gage and `terminating at the Zero graduation thereto to assure a more ac curate reading or indication of the depth of the liquid in theV main reservoir.

Another object is to construct the gageinv y such manner that convenient access may be had to both the sight tube and the stand pipe for cleansing purposes and also to facilitate the placing and removal of the connecting tube between the supplemental reservoir of the si and pipe and sight tube.

A further object is to provide simple means whereby the liquid in the gage tube may be replenished when desired.

Another object is to provide means where; by a plurality of gages for liquids for difcoV ferent liquid reservoirs may be combined in- Y a unitary structure and the accuracy of measurement in-both controlled by a single pump or equivalenic means for displacing theliquid from the gage.

Other objects and uses relating to specific parts of the apparatus will be brought outf in the following description.v f In the drawings Figure 1 isa face viewof a single gage and Vadjacent portion of the instrument upon which it is mounted, broken away.

Figure 2 is 'a verticalsectional view taken on line 2 2, Figure 1, showing in section a portion ofthe main liquid supply reservoir and pipe connectionsV between said reservoirl Vand the stand pipe of the gage,`said pipe connection being partly broken away iov indicate that the gage may be used in relatively remote or proximate relation to the reservoir. v Y

Figure 8 isa face view of a plural gage for indicating the depth or level of liquids in diderent reservoirs by embodying the same principle Aof operation as that shown in Figures 1 and 2.

kFigure l Vis a vertical sectional view taken "on line P-fl, Figure 3. Y

Figures 5 and 6 are lioriz'ontal sectional views taken on lines 5*5 and 6-6 respectively, FigureB;

These sight gages are adapted to be mounted upon an instrument board as A- or any other suitable part of a motor vehicle where it is conveniently visible to the operator and, as illustrated, in Figures 1 and 2 preferably comprises a one-piece cast' metal frame `-1-, a sight tube .2-,said` frame being provided with an upright stand pipe -3- and a horizontal cylinder -10`, the

lower end ot the stand pipe being enlarged to form a supplemental reservoir -4-.

The enlarged lower end or base of the stand pipe 3 is provided with a rearwardly extending offset -5- having a vertical opening (3- therethrough tor receiving the lower end ot the sight tube or gage -2- and a suitable screw plug -7- together with a suitable packing -8- between the upper end of the plug -7- and lower end ot the sight tube to torni a liquid and air tight joint between them.

The enlarged lower end or base of the stand pipe l 3- is threaded internally 'for receivingl a screw cap 9- which may be removed and replaced at will and forms a liquid tight joint with the lower end of the reservoir through the medium ot suitable packing SY- lhe lower wall ot the cylineer -l0 extends rearwardly over the uper end ot the age tube -2- and is provided with a cylindrical soclret in its un lmside tor receiving the upper end ot said l e and a suitable packing -S to trm a liquid and air tight joint between those parts.

rlhis lower side or por Qn of the cylinder -lO-- is thickened and provided with a lengthwise passage -llextending trom end to end of the cylinder and having one end connected b y a branch passage 1.2- to the interior of the corresponding end ot the cylinder and its other end communica ting through a branch passage -l"- with the interior ot the upper end ot the sight tube said passage llbeing extended through the front end ot the lower wall of the cylinder and is provided with a closure -l4- preferably in the form ot a screw or equivalent device which may be removed when desired to replenish the liquid in the sight tube` -2- and supplemental reservoir Jlby the use ot a hand dropper or other device inserted in the screw openings.

The reservoir -Jris ot greater diameter than the interior of the stand pipe --3- and sight tube -2- extends some distance below the lower end of the sight tube and underlying portion of the base of the trame 1 to permit convenient manipulation of the cap -9-, the upright par'f't'on wall between the supplemental reservoir liand opening -6- ,tor the lower end of the sight tube 2- and screw plug -7- is provided with a diagonally extending opening l5 registering with a corresponding diagonal opening i6- in the adjacent side of the plug 7 tor receiving a straight connecting tube -l7 having a passage ot small diameter therethrough.

rlhe lower end ot this connecting tube 17- when placed in operative position extends into close proximity to the bottom wall or cap 9* ot' the supplemental reservoir 4 while its upper end extends into the lower end of the sight tube -2- and terminates at approximately the level of the upper face ot the extension -5- or at the zero graduation of the sight tube.

The upper face of the plug -7- when adjusted tor use is disposed in a. horizontal plane slightly below the upper tace ot' the extension -5- to tornL a relatively small liquid pocket -18- surrounding the portion of the upper end of the connecting tube -17- which projects thro-ugh and above the upper tace of the plug 7- so as to establish and maintain an accurate reading for the liquid in the sight tube and to prevent complete expulsion of the liquid therefrom by the operation of the pump piston, prescnt y described.

rlhe rear end ot the cylinder '1.()- is threaded internally for receiving a threaded bushing -19 having a reduced threaded rear end --20- which extends through an opening in the instrument board #A and is clamped thereto by means of a nut -2lthereby firmly holding the entire gage in operative position upon the instrument board.

The front wall ot the upaer end ot the stand pipe -3- is provided with a branch passage -22- which is connected to one end of a t'ecd pipe 23- having its lower end extended into a main supply reservoir as *Q4- containing the liquid to be measured, said feed pipe being preferably extended to a point in `proximity to the bottom of the reservoir so as to assure the measurement of the liquid therein at all levels.

A suitable piston --25- is reciprocally movable within the cylinder -ll and is provided with a tubular stem -26- extending therethrough from end to end7 said stem being extended through a central opening in the bushing -19- and is provided with an operating handle -Q6- lby which the piston may be recipro-cated, said piston and its cylinder -lO- constituting what may be termed a hand pump, the object ot which is to replenish the air supply entrapped between the liquid in the reservoir 4P- and tank Q4- when necessary or desirable to assure accuracy ot indication ot the lepth gage particularly in cases where the accuracy of indication is affected by varying atmospheric temperatures as will be hereinafter more fully explained.

The construction shown in Figures 3 to G inclusive is substantially the same as that shown in Figures l and 2 except that the trame is enlarged suiliciently to receive a plurality of, in this instance two, stand pipes -3- and -3 and a corresponding num ber of suplemental reservoirs iland -4-, sight tubes-Qand -2- and restrieted connecting tubes -17- and 17-, the upper ends of the stand pipes being connected by separate tubes -23- and QP/ to separate reservoirs containing the same or different liquids, the depth or level of which is to be indicated by their respective sight tube.

Vhen two of these indicating devices are used in the same unit the liquid in both sight tubes h2h and 2- may be replenished through the lengthwise opening in the stem 2(5* of the piston -25- by simply withdrawing said piston outwardly and then injecting the liquid through the central passage therein into the front end oi the cylinder and thence through the branch passage -12, main passage -lland branch passage -13- into one or the other of the sight tubes as regulated 4by an adjusting screw or valve ll-A as shown more clearly in Figure 5.

Substantially one-half of the inner end of this valve -.-l4- is cut away while the remaining halil extends across the adjacent ends of opposite alined branch passages l3- and -13- leading to the upper ends of their respective sight tubes -2- and hso that when the valve 14- is turned to one position communication will be established between one of these branch passages as -l3- and the main passage -11- and at the same time cutting off communication bebetween said main passage and the other branch passage.

Or, when adjusted to a third position, both branch passages will be in open communication with the main passage ll.

The outer end of the valve lllconstitutes a handle by which it may be turned and is provided with a. pointer -llC- to indicate the position of the valve and preferably faces in the direction of the opening side of the valve. y

When the main supply tank or reservoir is empty or substantially so, as indicated in .Figure 2, the liquid in the sight tube -2- will recede therefrom through the pipe 17- into the reservoir-1 until it reaches the level of the upper end of the pipe 17 at which time a relatively small quantity of the liquid in the sight tube -2 will be retained in the bottom thereof or in the pocket -8 to the level of the upper end of the pipe -17- which is the Zero level in the sight tube indicating that thetank is empty.

Now, when liquid to be measured` is introduced into the main supply tank *2li-1 it will gradually rise in the upright portion or" the tube thereby trapping the air in the tube 23 and stand pipe *3 in contact with the lgage liquid in the reservoir -4 and force said gage liquid from said reservoir .thru the pipe -l7 and into the sight tubes -2- a distance corresponding to the level of the liquid to be measured in the main supply` reservoir 2a- The sight tube or tubes are suitably graduated to indicate units of liquid measurement finger or thumb and then pushed inwardly to force the Aliquid from the sight tube 2+ into the reservoir +4-, thus raising the level of the liquid in the reservoir -4- and causing the entrapped air to displace the liquid from the lower end of the tube -23- until it enters the main tank -24- from which it may be vented through the usual vent provided in tanks ot this character.

Then, by removing the finger froml the outer open end of the tubular stem f9- permits the liquid from the main reservoir Q4-4 to reenter the adjacent enol of the pipe *S23- thereby compressing the air in the tube -23- andV stand pipe 9- and thereby forcing the liquid from the supplemental reservoir -4` back through the restrictedA tube 17+ in the sight tube 2* to indicate the level of the liquid inthe mainI supply reservoir 2%- thus completing the cycle ofoperation which is the same for both the single and double indicators.

The interior diameter of the pipe leading from the main supply tank to thestand pipe is preferably smaller thanthat of the sight tube while the diagonal pipe 17; connect- .ing the reservoir-L with thelower end of the sight tube is relatively smaller than the pipe leading from the main supply tank tothe stand pipeto assure greater accuracy of measurement. v

For example, if the tank 24; is empty the pressure ofthe air in the tube 23- and stand'pipe -3- will be relieved thus permitting the-upiow of the liquid in the reservoir -l-and a corresponding downl flow of4 the liquid' inthe sight tube 2- through the restricted tube '-17- to the same level aszthatV in the reservoir thus indicating by the sight'tubethe emptiness `of the tank;

The maximum capacity of the reservoir 4- is approximately equal tothe capacity of the sight-tube #-2- from the'l'ow'er end of the tube -l7- to the top of the sight tubeV so that it may ebb and flow from thel reservoir into the sight tube and vice versa as the level of the liquid in the reservoir varies.`

When the tank -24- is iilled it traps the air in the tube -23- and stand pipe -3- thereby depressing the level of the liquid in the Vreservoir 4- and forcing it through the restricted tube -17 into the sight tube -Qfthus givingan accurate indication in the sight tube of the level of the liquid in the tank.

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In the event that the air in tube -23- is expanded because of heat, some of the air, due to the expansion, will escape through passage -13- and piston stem 26, or the air will escape from the submerged end of tube -23 and thence out through the vent in tank 2li depending upon the relation of the head of the liquid in tank 24 to the head of the liquid in tube 2. The result will be that when the cause for the expansion of the air in tube -23- is removed the air will contract resulting in an inaccurate reading on the scale. Under these conditions it is necessary, in order to reset the device for accurate measurement, to replace in tube -23- the air which was lost through expansion, and this is accomplished in the followingmanner: The piston Q5 is drawn outwardly and a finger or thumb placed over the end of the pistonstem 26 to close the opening` therethrough. The piston 25 is then forced inwardly compressing the air in front of it against the liquid in sight tube 2 which w l cause this liquid to be Arer-ced downwari 3 through restricted passage l'i' into reserv ir i at which time the compressed air will pass upwardly through the liquid into tube An excess amount of air thus forced into tube 23 will depress the liquid in tube 23 and the excess air will escape from the submerged end of tube Q3.

W'hat I claim is In a device for indice-ting` the level of liquid in a container7 an upright reservoir, a pipe with relatively small diameter, communicating with said reservoir and extending* downwardly into said container near the bottom thereof, an upright sight-tube having a. bottom wallV disposed in a plane some distance above the bottom of the reservoir, a conduit extending from the interior of the reservoir near the bottom thereof through the bottom of the sight-tube and having its upper end terminating` within the sighttube an appreciable distance above the bottom thereof to determine the Zero level of the liquid therein and also to allow a limited quantity of the liquid to be trapped in the lower end of the sight-tube when the level of the liquid in the sight-tube is depressed to the level of the upper end of the conduit.

In witness whereof l have hereunto set my hand this 12th day of August, 1926.

PETER J. SEFERLIS. 

